As helpful as Punnett squares are for studying Mendelian genetics, many students find them baffling. This series of three worksheets walks them through the process step by step. Once students complete the third worksheet they’ll have a helpful reference sheet showing all of the possible gene crosses. Then they can use this sheet throughout their genetics study to determine genotypes based on frequencies of traits. This simple, no-prep activity can be done as a class or individually.
Use this to learn and reinforce answers to questions such as:
❑ How do you write a genotype using letters?
❑ How many combinations of genotypes are there for a given cross?
❑ How many combinations of phenotypes are there for a given cross?
❑ Are genes always obvious in progeny? Why or why not?
Answer Keys and Teacher Notes address most questions and issues that might arise in this study—you shouldn’t have to do any outside research unless you want to.
Concepts Addressed
♦ Genes are passed from parent to offspring in a specific way.
♦ Each parent passes half of its genes to each of its offspring
♦ Offspring may or may not appear like their parents depending which genes are transmitted.
Materials Needed
Copies of student sheets
Time Required
This activity takes about 40 minutes though discussion can increase that time
Student Sheets
Three step-by-step worksheets
